1. Field of the Invention
The present invention relates to the field of information handling systems, and more particularly to a method and system for controlling delivery of electrical power to a portable information handling system.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems configured as portable computers have grown increasingly favored by businesses and individuals due to the flexibility of their use. Portable computers typically include a battery to power components so that the portable computer may be carried and used independent of fixed power sources. Although internal power sources provide greater flexibility, they typically have a limited duration and need periodic recharging. If portable computers are not recharged before the battery discharges completely, the portable computer may shutdown resulting in a loss of active data and an inability by the user to turn the portable computer system on again unless an external power source is connected. A method and system for determining external power availability is generally described in U.S. Pat. No. 6,597,565 issued to Kluth et al., issued on Jul. 2, 2003, which by this reference is incorporated herein for all purposes.
Many of today's airline, automobile and train passengers carry portable computers on-board for in-transit use. However, since portable computers consume relatively large amounts of power, the batteries that operate the device do not last for more than typically 2–6 hours. On long trips or when the battery is weak, a computer can drain the battery quite rapidly. For the traveler attempting to minimize the weight of their computer luggage, heavy spare batteries are undesirable and still only provide a nominal amount of additional computer operating time.
Because the use of computers during travel is so common, some airlines and trains have begun offering in-seat power systems for powering devices such as portable computers. These power systems often provide DC power via an in-seat connector that is typically either a modified version of the standard auto cigarette lighter socket or a manufacturer-specific plug configuration. Standard power adapters used with portable computers, however, typically are designed to work with AC power. As will be understood by those of skill in the art, different power adapter system components are required when operating a portable computer on DC power instead of AC power. There is a need, therefore, for the portable computer to receive information regarding the type of power being supplied to the power adapter. In addition, there is a need for a method and system to enable a portable computer to modify its operating parameters to enter various charging modes and various power consumption modes depending on the type of power source supplying power to its power adapter.